Surface emitting laser, surface-emitting-laser array, and image forming apparatus

摘要

The present invention provides a surface emitting laser that provides a sufficient optical output and is suitable as a light source intended for electrophotographic apparatuses, and a surface-emitting-laser array and an image forming apparatus each including the surface emitting laser.;The surface emitting laser includes a first stepped structure on a front surface of a front mirror. In the first stepped structure, a difference L between an optical path length in a first area and an optical path length in a second area satisfies the following expression:
(¼+N)λ<|L|<(¾+N)λ
where N is an integer.

主权项

1. A surface emitting laser configured to oscillate at a wavelength λ, comprising:
a substrate; a multilayer structure provided on the substrate and in which layers including a rear mirror, an active layer, and a front mirror are stacked; and a first stepped structure provided on a front surface of the front mirror and including a portion extending in a first area defined in a central part of an emission area and a portion extending in a second area defined on the outer side of the first area within the emission area, the portions having different heights, wherein, in terms of an optical path length from a plane defined on the outside of the surface emitting laser and extending perpendicular to a stacking direction of the multilayer structure to the front surface of the front mirror, a difference L between the optical path length in the first area and the optical path length in the second area satisfies the following expression:
(¼+N)λ<|L|<(¾+N)λ where N is an integer, and wherein the first stepped structure has an optical thickness that is an integral multiple of λ/2 in each of the first area and the second area.